startOf always returns non utc date even if date was utc

[NuclleaR]

Describe the bug
Jiffy(Jiffy().utc()).dateTime.isUtc returns true
Jiffy(Jiffy().utc()).startOf(Units.MONTH).isUtc returns false

Expected behavior
If date was in UTC, startOf should return UTC DateTime object

Smartphone (please complete the following information):

• Device: iPhone12
• OS: iOS14

[omidraha]

Jiffy(Jiffy().utc()).startOf(Units.DAY).dateTime.toUtc();

[RobertHeim]

The problem I see is that we cannot get the start/end in a specific timezone. It always uses the local timezone.

Jiffy(DateTime.now().toUtc()).startOf(Units.MONTH).utc();
// actually: 2021-09-30 22:00:00.000Z
// expected: 2021-10-01 00:00:00.000Z

[mindfaq13]

any news on this one ?

I chose Jiffy for date-time manipulation since it promises to make tasks like date/time diff calculation easier. Dart's built-in DateTime only allows expressing time difference in milliseconds, seconds all the way up to days - but no months or years since these two are a bit tricky to get right.
I thought Jiffy would make for a good DateTime replacement, but startOf / endOf methods as of now are pretty much useless if you try to manipulate UTC timestamps, so I'm forced to look for an alternative.
Or maybe there is an obvious workaround I fail to see ?

[RobertHeim]

well I think strictly speaking UTC is not a time zone, but we need a time zone to calculate startOf / endOf. I guess most people expect that the calculation for a UTC DateTime should be done in time zone GMT and not in the local time zone.